A method for preparing high-purity Bi2O2Te materials using an oxide precursor method

Abstract

This invention relates to the field of thermoelectric / photoelectric materials technology, specifically to a method for preparing high-purity Bi2O2Te material using an oxide precursor method. The key technical points are: bismuth and tellurium sources are ground and mixed uniformly in an agate mortar according to a stoichiometric ratio of Bi to Te of 2:1 to obtain a mixed powder; the mixed powder is heat-treated under a reducing atmosphere, and after cooling, Bi2O2Te material is obtained. The bismuth source is selected from one or both of Bi2O3 powder and Bi powder, and the tellurium source is selected from one or both of Te powder and Bi2Te3 powder. A pure-phase Bi2O2Te material with excellent crystallinity was successfully synthesized at a relatively low temperature of 550-600℃, significantly reducing the reaction temperature, effectively saving energy consumption, and avoiding the problem of material decomposition caused by high temperatures.

Description

Technical Field

[0001] This invention relates to the field of thermoelectric / photoelectric materials technology, specifically to a method for preparing high-purity Bi2O2Te materials using an oxide precursor method. Background Technology

[0002] With the increasing prominence of energy crises and environmental problems, thermoelectric conversion technology, as a clean energy technology capable of directly converting heat energy into electrical energy, has received widespread attention. 2 σT / κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the absolute temperature. An ideal thermoelectric material should have a high power factor (ST / κ). 2 Transition metal chalcogenides possess unique electrical and thermal properties, making them promising candidates for applications in thermoelectric conversion, photoelectric detection, and other fields.

[0003] Bi₂O₂Te, a novel layered oxide-chalcogenide, combines the stability of oxides with the excellent electrical transport properties of chalcogenides, showing potential application value in the thermoelectric field. Its layered structure facilitates the formation of low thermal conductivity while exhibiting high electrical conductivity and Seebeck coefficient, making it a promising high-performance thermoelectric material. Currently, the main synthesis methods for Bi₂O₂Te include solid-state reaction and chemical vapor deposition (CVD). However, traditional solid-state reaction methods typically require high-temperature (>700℃) and long-term sintering, resulting in high energy consumption and difficulty in controlling product purity; CVD methods suffer from complex equipment, low yield, and are unsuitable for large-scale production.

[0004] Therefore, it is of great significance to develop a simple, low-cost, and high-purity method for synthesizing Bi2O2Te. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a solution that can effectively solve the problems of high energy consumption and difficulty in controlling product purity caused by high temperature and long time sintering in the traditional solid-state reaction method, as well as the problems of complex equipment, low yield and unsuitability for large-scale production in the chemical vapor deposition method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing high-purity Bi2O2Te material using an oxide precursor method, the method comprising:

[0008] (1) Place the bismuth source and the tellurium source in an agate mortar and grind them evenly according to the stoichiometric ratio of Bi to Te of 2:1 to obtain a mixed powder;

[0009] (2) The mixed powder is heat-treated in a reducing atmosphere and cooled to obtain Bi2O2Te material.

[0010] Furthermore, the bismuth source is selected from one or two of Bi2O3 powder and Bi powder; the tellurium source is selected from one or two of Te powder and Bi2Te3 powder.

[0011] By combining different bismuth and tellurium sources in the above technical solutions, the reaction pathway can be controlled.

[0012] Furthermore, in step (2), the heat treatment process includes:

[0013] Heat to 300-400℃ at a heating rate of 5-10℃ / min, hold for 12-18 hours, and then heat to 550-650℃ at a heating rate of 5-10℃ / min, hold for 2-4 hours.

[0014] Furthermore, the preferred heat treatment process includes: heating to 350°C at 5°C / min, holding at that temperature for 15 hours, and then heating to 600°C at 5°C / min and holding at that temperature for 2 hours.

[0015] In the above technical solutions, if the heat treatment temperature is too low or the time is too short, the reaction will be incomplete and unreacted raw materials may be present in the product; if the temperature is too high or the time is too long, the product may decompose or the grains may grow excessively, affecting the material properties.

[0016] Furthermore, the heat treatment is followed by an annealing step, specifically: the obtained material is heated to 600°C at a heating rate of 5-10°C / min under an inert atmosphere, held at that temperature for 10 hours, and then cooled to room temperature.

[0017] Furthermore, the preferred annealing process is to heat the material to 600°C at a rate of 5°C / min under an argon atmosphere.

[0018] Furthermore, the reducing atmosphere is a mixture of hydrogen and inert gas, wherein the volume fraction of hydrogen is 5%, and the remainder is inert gas.

[0019] Furthermore, the inert gas is argon.

[0020] Furthermore, the inert atmosphere in the annealing process is an argon atmosphere.

[0021] In the above technical solution, hydrogen acts as a reducing agent to promote the reduction reaction of oxides; inert gas acts as a carrier gas and dilution gas to ensure the safety of the reaction. Too low a hydrogen content results in insufficient reducing power; too high a content poses safety hazards.

[0022] Furthermore, the grinding and mixing time is 40-90 minutes to ensure that the raw materials are fully and evenly mixed.

[0023] Furthermore, the particle size of the mixed powder is 1-10 μm. This particle size range is conducive to the uniform mixing of raw materials and the full progress of solid-phase reaction. If the particle size is too large, the reaction kinetics will be slow; if the particle size is too small, it may cause agglomeration problems.

[0024] In a second aspect, the present invention also provides a method for preparing high-purity Bi2O2Te materials using an oxide precursor method, wherein the Bi2O2Te materials are prepared according to the method described in the first aspect.

[0025] Thirdly, the present invention also provides the application of the Bi2O2Te material described in the second aspect in thermoelectric conversion devices or photoelectric detection devices. This Bi2O2Te material can be fabricated in bulk, thin film, or other forms for use in the preparation of thermoelectric generators, thermoelectric coolers, photoelectric detectors, and other devices.

[0026] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0027] 1. This invention utilizes an oxide precursor method, mixing bismuth and tellurium sources in stoichiometric ratio and then heat-treating under a reducing atmosphere to successfully synthesize pure-phase Bi2O2Te materials at a relatively low temperature of 550-600℃. This significantly reduces the reaction temperature (compared to the traditional solid-phase reaction method >700℃), effectively saving energy consumption and avoiding the problem of material decomposition caused by high temperature.

[0028] 2. This invention employs a two-stage heating heat treatment process combined with subsequent annealing. By holding the temperature at a low temperature for a long time to promote the full reaction of the precursor, and holding the temperature at a high temperature for a short time to complete crystallization, followed by annealing to further improve the crystallinity, the generation of impurity phases is effectively suppressed, resulting in Bi2O2Te material with high phase purity and excellent crystal quality.

[0029] 3. By flexibly selecting a combination of various bismuth sources (Bi2O3, Bi powder) and tellurium sources (Te powder, Bi2Te3), this invention has constructed multiple feasible synthetic routes. It can not only utilize the high reactivity of the metal elements to accelerate the reaction, but also use the stability of the compound precursors to control the reaction process, which significantly improves the adaptability of the process and the diversity of raw material sources.

[0030] 4. The process of this invention is simple, requiring only two core operations: grinding and mixing and heat treatment. It does not require complex equipment, the reaction conditions are mild and controllable, and the product has high purity and good repeatability. It overcomes the shortcomings of chemical vapor deposition method, such as complex equipment and low yield, and is more suitable for large-scale industrial production. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0032] Figure 1 This is a schematic diagram of the synthesis process of Bi2O2Te material in Examples 1-4 of the present invention;

[0033] Figure 2 The images show the XRD patterns of Bi2O2Te materials obtained in Examples 1-4 of this invention, where (a) is the individual XRD pattern of Example 1 and a schematic diagram of the crystal structure of Bi2O2Te material, and (b) is the XRD comparison pattern of Examples 1-4.

[0034] Figure 3 The XPS spectra of Bi2O2Te materials obtained in Examples 1-4 of this invention are shown, where (a) represents the Bi 4f energy level, (b) represents the O 1s energy level, and (c) represents the Te 3d energy level.

[0035] Figure 4 The above are XPS spectra of the Bi2O2Te material prepared in Example 1 of this invention, where (a) represents the Bi 4f energy level, (b) represents the O1s energy level, and (c) represents the Te 3d energy level. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0037] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail. The terms “comprising,” “including,” “having,” “containing,” etc., as used herein are open-ended terms, meaning that they include but are not limited to. Unless the context clearly indicates otherwise, the expressions “a” and “an” as used herein include plural references. It should be noted that “first,” “second,” etc., are used merely for convenience of description and distinction and should not be construed as indicating or implying relative importance. The term “about” as used herein indicates a range of ±20% of the following numerical value. In some embodiments, the term “about” indicates a range of ±10% of the following numerical value. In some embodiments, the term “about” indicates a range of ±5% of the following numerical value. The invention is further described below with reference to embodiments.

[0038] Example: Refer to Figures 1 to 4 .

[0039] This invention provides a method for preparing high-purity Bi₂O₂Te materials using an oxide precursor method. A schematic diagram of the synthesis process is shown below. Figure 1 As shown, by employing the oxide precursor method, pure-phase Bi2O2Te material was successfully synthesized at a relatively low temperature of 550-600℃ after mixing bismuth and tellurium sources in stoichiometric ratio and heat-treating under a reducing atmosphere. This significantly reduced the reaction temperature (compared to the traditional solid-state reaction method >700℃), effectively saving energy consumption and avoiding the material decomposition problem caused by high temperature.

[0040] The raw materials used in the embodiments of this invention are all commercially available analytical grade or high-purity reagents, and their specific sources are as follows:

[0041] Bi2O3 powder: purity ≥99.9%, particle size 1-5μm, purchased from Aladdin Reagent Company;

[0042] Bi powder: purity ≥99.99%, particle size 5-10μm, purchased from Aladdin Reagent Company;

[0043] Te powder: purity ≥99.99%, particle size 5-10μm, purchased from Aladdin Reagent Company;

[0044] Bi2Te3 powder: purity ≥99.9%, particle size 5-10μm, purchased from Aladdin Reagent Company.

[0045] The preparation method of the present invention provides the following several embodiments:

[0046] Example 1

[0047] (1) Raw material preparation: Weigh Bi2O3 powder (purity 99.9%, particle size 1-5μm), Bi powder (purity 99.99%, particle size 5-10μm) and Te powder (purity 99.99%, particle size 5-10μm), and mix them according to the Bi:Te atomic ratio of 2:1. The specific ratio is Bi2O3:Bi:Te=1:2:2 (molar ratio);

[0048] (2) Grinding and mixing: Place the weighed powder in an agate mortar and grind it by hand for 1 hour to ensure that the raw materials are fully mixed and uniform, and obtain mixed powder;

[0049] (3) Heat treatment: The mixed powder is placed in a tube furnace and heated to 350°C at 5°C / min under a mixed atmosphere of 5%H2 / 95%Ar. The temperature is held for 15 hours, then heated to 600°C at 5°C / min and held for 2 hours. The mixture is then naturally cooled to room temperature to obtain Bi2O2Te material.

[0050] Example 2

[0051] (1) Raw material preparation: Same as in Example 1, Bi2O3:Bi:Te = 1:2:2 (molar ratio);

[0052] (2) Grinding and mixing: Grind by hand for 1 hour;

[0053] (3) Heat treatment: The mixed powder was placed in a tube furnace and heated to 350°C at 5°C / min under a mixed atmosphere of 5% H2 / 95% Ar. The temperature was held for 15 hours, and then heated to 600°C at 5°C / min. The temperature was held for 2 hours and then cooled to room temperature naturally to obtain Bi2O2Te material. The obtained material was placed in a tube furnace again and annealed at 600°C at 5°C / min under an argon atmosphere. The temperature was held for 10 hours and then cooled to room temperature naturally.

[0054] Example 3

[0055] (1) Raw material preparation: Weigh Bi2O3 powder (purity 99.9%, particle size 1-5μm) and Bi2Te3 powder (purity 99.9%, particle size 5-10μm), and mix them according to the Bi:Te atomic ratio of 2:1. The specific ratio is Bi2O3:Bi2Te3=2:1 (molar ratio).

[0056] (2) Grinding and mixing: Place the weighed powder in an agate mortar and grind it by hand for 1 hour to ensure that the raw materials are fully mixed and uniform, and obtain mixed powder;

[0057] (3) Heat treatment: The mixed powder is placed in a tube furnace and heated to 350°C at 5°C / min under a mixed atmosphere of 5%H2 / 95%Ar. The temperature is held for 15 hours, then heated to 600°C at 5°C / min and held for 2 hours. The mixture is then naturally cooled to room temperature to obtain Bi2O2Te material.

[0058] Example 4

[0059] (1) Raw material preparation: Same as in Example 3, Bi2O3:Bi2Te3=2:1 (molar ratio);

[0060] (2) Grinding and mixing: Grind by hand for 1 hour;

[0061] (3) Heat treatment: The mixed powder was placed in a tube furnace and heated to 350°C at 5°C / min under a mixed atmosphere of 5% H2 / 95% Ar. The temperature was held for 15 hours, and then heated to 600°C at 5°C / min. The temperature was held for 2 hours and then cooled to room temperature naturally to obtain Bi2O2Te material. The obtained material was placed in a tube furnace again and annealed at 600°C at 5°C / min under an argon atmosphere. The temperature was held for 10 hours and then cooled to room temperature naturally.

[0062] The differences between the above four embodiments are the combination of raw materials and whether or not annealing treatment is performed.

[0063] The raw material combinations differ: Examples 1 and 2 use Bi₂O₃ powder, Bi powder, and Te powder as raw materials, with a specific molar ratio of Bi₂O₃:Bi:Te = 1:2:2. In this combination, Bi powder and Te powder first react in situ to generate a Bi₂Te₃ intermediate phase, which then reacts with Bi₂O₃ to form the final Bi₂O₂Te. Examples 3 and 4 use Bi₂O₃ powder and Bi₂Te₃ powder as raw materials, with a molar ratio of Bi₂O₃:Bi₂Te₃ = 2:1. This combination involves directly mixing the two compounds for a solid-phase reaction.

[0064] The post-treatment processes differ (whether or not annealing is performed): Examples 1 and 3 only undergo basic heat treatment (holding at 350°C for 15 hours in a 5% H2 / Ar atmosphere, then raising the temperature to 600°C and holding for 2 hours), without any additional annealing steps. Examples 2 and 4, after completing the basic heat treatment, add an annealing treatment (holding at 600°C for 10 hours in a pure Ar atmosphere).

[0065] Material characterization and experimental analysis

[0066] Phase analysis of the samples prepared in Examples 1-4 was performed using X-ray diffraction (XRD, Rigaku Ultima IV, Cu Kα radiation, λ=1.5406 Å), with a scanning range of 10-90º and a scanning speed of 5º / min. The surface chemical states of the samples were analyzed using X-ray photoelectron spectroscopy (XPS, Thermo Scientific K-Alpha, Al Kα radiation), with binding energy calibrated at C1s (284.8 eV).

[0067] XRD analysis was performed on the Bi2O2Te materials prepared in Examples 1-4, and the results are as follows: Figure 2 As shown. Figure 2 Image (a) shows the individual XRD pattern of Example 1 and a schematic diagram of the crystal structure of the Bi2O2Te material. Figure 2 As can be seen from (a) in Example 1, the diffraction peaks of Example 1 are in good agreement with the standard crystal structure data of Bi2O2Te. No impurity phases such as Bi2O3, Bi, Te, and Bi2Te3 were detected, indicating that Example 1 successfully synthesized pure phase Bi2O2Te material with good crystallinity. Figure 2 Figure (b) shows the XRD patterns of Examples 1-4. As can be seen from the figure, the diffraction peaks of all examples are in good agreement with the crystal structure data of Bi₂O₂Te, and no obvious impurity phases were detected, indicating that pure-phase materials were successfully synthesized in Examples 1-4. It is noteworthy that in the annealed samples of Examples 2 and 4, the diffraction peak at 2θ≈33.5° is significantly sharper than that of Examples 1 and 3, indicating that after annealing at 600℃ for 10 hours, the crystallinity of the material is further improved, the grain size is increased, and the crystal structure is more complete. This is because annealing provides sufficient energy and time for atomic diffusion and lattice rearrangement, promoting grain growth and repair of lattice defects, thereby enhancing the intensity of the diffraction peaks and reducing the full width at half maximum (FWHM).

[0068] XPS analysis was performed on the Bi2O2Te materials prepared in Examples 1-4, and the results are as follows: Figure 3 As shown. Figure 3 (a) shows the Bi 4f energy level spectra of the four samples. All samples exhibit two characteristic peaks at approximately 159 eV and 164 eV, corresponding to Bi 4f, respectively. 7 / 2 and Bi 4f 5 / 2 The spin-orbit splitting energy is approximately 5 eV, indicating that Bi in all four samples exists in the +3 oxidation state, and that different combinations of raw materials and annealing treatments did not change the chemical oxidation state of Bi. Figure 3(b) shows the O 1s energy level spectra of the four samples. A single symmetrical peak appears at about 530 eV, which is attributed to the characteristic binding energy of the Bi2O2Te lattice oxygen. No obvious signals of surface adsorbed oxygen or hydroxyl groups were detected, indicating that the sample surface is clean. Figure 3 (c) shows the Te 3d energy level spectra of the four samples. All samples exhibit two characteristic peaks at approximately 576 eV and 586 eV, corresponding to Te 3d... 5 / 2 and Te 3d 3 / 2 The spin-orbit splitting energy is about 10 eV, indicating that Te exists in the +4 oxidation state. No characteristic signal of elemental Te (about 573 eV) was detected, further confirming the successful synthesis of the target product.

[0069] To further analyze the chemical state and coordination environment of each element, peak fitting was performed on the fine XPS spectrum of the sample from Example 1. The results are as follows: Figure 4 As shown, where, Figure 4 (a) in the figure is the fitted spectrum of the Bi 4f energy level, which can be fitted as two sets of spin-orbit splitting peaks with binding energies of 158.8 eV and 164.1 eV, respectively (Bi 4f). 7 / 2 and Bi 4f 5 / 2 ), corresponding to Bi 3+ chemical state; Figure 4 (b) in the figure is the fitted spectrum of the O 1s energy level, which shows a single symmetric peak at 529.8 eV, which is attributed to lattice oxygen. Figure 4 (c) in the figure is the fitted spectrum of the Te 3d energy level, which can be fitted as two sets of spin-orbit splitting peaks with binding energies of 575.8 eV and 586.2 eV, respectively (Te 3d 5 / 2 and Te 3d 3 / 2 ), corresponding to Te 4+ The chemical state of Bi2O2Te was determined. The fitting results showed good agreement with the standard spectrum, further confirming the successful synthesis of Bi2O2Te, and no obvious elemental Bi or Te was found in the sample. Combined XRD and XPS analyses confirmed that pure-phase Bi2O2Te materials were successfully prepared using the methods described in Examples 1-4, with annealing effectively improving the crystallinity of the material. In summary, the Bi2O2Te material preparation method provided by this invention has advantages such as simple process, low cost, high product purity, and excellent performance, laying the foundation for the large-scale production and practical application of Bi2O2Te-based thermoelectric materials.

[0070] This invention successfully synthesized Bi₂O₂Te material via an oxide precursor method. The raw material combination and annealing process significantly influence the purity and crystallinity of the product. The raw material combination is a key factor affecting the reaction pathway and product phase. Examples 1 and 2 used Bi₂O₃, Bi powder, and Te powder as raw materials. The Bi₂Te₃ intermediate phase was generated through an in-situ reaction between Bi powder and Te powder, which then reacted with Bi₂O₃ to form Bi₂O₂Te. Examples 3 and 4 used Bi₂O₃ and Bi₂Te₃ as raw materials, directly synthesizing the target product through a solid-state reaction. Both raw material combinations yielded pure-phase Bi₂O₂Te under the same heat treatment conditions, indicating that both precursor systems provided by this invention have good feasibility. In contrast, Comparative Example 1, which used Bi powder and Te powder for direct reaction, produced unreacted Bi and Te elemental impurities, indicating that the reaction was difficult to complete without the participation of Bi₂O₃. Comparative Example 2, using Bi₂O₃ and TeO₂ as raw materials, produced mainly Bi₂Te₃ and Bi₂O₃, indicating that TeO₂ preferentially reduces to elemental Te under a reducing atmosphere and is unlikely to directly participate in the formation of Bi₂O₂Te. The annealing process has a significant impact on the crystallinity of the material. Comparing Examples 1 and 2, and Examples 3 and 4, it is evident that after annealing at 600℃ for 10 hours, the XRD diffraction peaks of the samples (especially the characteristic peak at 2θ≈33.5º) were significantly sharper. This indicates that annealing provides sufficient time and energy for atomic diffusion and lattice rearrangement, promoting grain growth and lattice defect repair, thereby effectively improving the crystallinity of the material. Therefore, adding an annealing step after basic heat treatment is an effective means to optimize the crystal structure of Bi₂O₂Te material. In summary, the Bi2O2Te material preparation method provided by this invention achieves controllable preparation of pure-phase products through optimized raw material combination and annealing process. It has advantages such as simple process, low cost, and high product purity, laying the foundation for the large-scale production and practical application of Bi2O2Te-based thermoelectric materials.

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing high-purity Bi₂O₂Te material using an oxide precursor method, characterized in that the method... include: (1) Place the bismuth source and the tellurium source in an agate mortar and grind them evenly according to the stoichiometric ratio of Bi to Te of 2:1 to obtain a mixed powder; (2) The mixed powder is heat-treated in a reducing atmosphere and cooled to obtain Bi2O2Te material.

2. The method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to claim 1, characterized in that, The bismuth source is selected from one or two of Bi2O3 powder and Bi powder; the tellurium source is selected from one or two of Te powder and Bi2Te3 powder.

3. The method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to claim 1, characterized in that, In step (2), the heat treatment process includes: Heat to 300-400℃ at a heating rate of 5-10℃ / min, hold for 12-18 hours, and then heat to 550-600℃ at a heating rate of 5-10℃ / min, hold for 2-4 hours.

4. A method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to any one of claims 1-3, characterized in that, The heat treatment is followed by an annealing step, which involves heating the obtained material to 600°C at a heating rate of 5-10°C / min under an inert atmosphere, holding it at that temperature for 10 hours, and then cooling it to room temperature.

5. The method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to claim 1, characterized in that, The reducing atmosphere is a mixture of hydrogen and inert gas, wherein the volume fraction of hydrogen is 5% and the remainder is inert gas.

6. The method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to claim 4, characterized in that, The inert atmosphere used in the annealing process is argon.

7. The method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to claim 1, characterized in that, The grinding and mixing time is 40-90 minutes.

8. The method for preparing high-purity Bi₂O₂Te material using an oxide precursor method according to claim 1, characterized in that, The particle size of the mixed powder is 1-10 μm.

9. A method for preparing high-purity Bi₂O₂Te material using an oxide precursor, characterized in that, The Bi2O2Te material is prepared by the method according to any one of claims 1-8.

10. The application of the Bi2O2Te material according to claim 9 in thermoelectric conversion devices or photoelectric detectors.

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